How to Recover/Replace ECU Thread

Looking at the Toyota warranty manual today, it started in 2018. The install process doesn't say that the ecm needs programmed, but in older years it does. Hopefully the handshake works for you.

 

The paperclip method of reset does not appear to work for 2021s, it became pretty obvious why when I looked real close and there’s no pin connection in slot #13 haha. I’ll try techstream/ho tuner vin edit next.

Edit: The “Vin Wizard” in hp tuners editor does not appear to present in the current version/2021 Tundras as an option.

 

do the pushbutton start trucks still have the little red security light that blinks when the key/fob isnt in the truck?

 

Mine is keyed, it does show the red car/lock before the key is put in. Once the key is in the ignition it stops (with the new ECU as well).

 

Okay so was able to use the VF Tuner dongle with techstream which is really a tactrix openport 2.0 that is colored orange haha. I got techstream version 17.x working which goes through 2021/2022 (there is an amazing techstream version 12.x available that is self contained and easy to use, but only works through about 2017/2018).

I got the new ECU written to use my old VIN and was successful. However still crank no start for the engine. I'll have to see if there is something else you have to do, otherwise it may be the stock tune doesn't like all the mods and/or a bad relay (pump/etc.).

 

I know for the earlier models pins 4 and 13 are used where. Pin 13 is supposed to be manufacturer specific timing/abs but resets the ecu. Earlier models you had to leave driver side door open too.
Pin 13 for 2021 still shows it being used for TC.
@e30cabrio had to try several times to get it to start.

 

If the security light goes out when you put the key in, that should mean the immobilizer module and the new ecu are communicating properly. Did you let it sit with the key "on" for 30-45 minutes just to be sure the modules have fully registered with each other?

Any trouble codes stored?

 

Update: I got a 2 day subscription to TIS to read the manuals. What is interesting is other models like the Highlander have more complex ECU registrations. However for 2016-2021s it actually appears to be very simple, mainly two relearns/clearing are recommended. Will try these out and report back. There does not appear to be a manual relearn/ECU reset outside of using techstream for 2016-2021. It even says removing the battery terminal does not reset the fuel trims/etc. like you would expect to do after changing/cleaning a throttle body (as an example).

 

Thanks for the clarification and makes sense how certain ones work while others dont.

 

So using techstream was able to easily clear the learned values and reset the other learned memory. The trucks first crank did turn on then stopped, similar behavior I have seen after a major change (like injectors). Following cranks/starts did not turn on, just cranking. Thus I think everything is fine, but the supercharger + mods (injectors/pump/etc.) may be too much for the 2021 OEM tune, so likely going to follow the original Magnuson VF tune process now (then HP tuners later if this works).

 

You are pretty much in uncharted territory as far I know in dealing with a 2021 ECU. What you learn will be helpful for other with late model 5.7's.

 

So reading in TIS some more it recommends to crank for 10secs minimum (which seems like forever) then if any DTCs (error codes) come up that tells you what the issue is. For example if the immobilizer was the issue it would make a DTC after 10 secs, etc. in my case I tried this and get no DTCs so I am pretty sure it’s a stock tune issue. Very interesting for sure, hopefully it’s not like a random relay or something. Thanks again for everyones help and once we figure this out ill post a run down on what to do for the newer years.

 

Stock tune seems like a weird issue. I would expect it to run pretty fine, maybe a bit rich and throw a rich code. But the ECM has a lot of leeway with fuel trims to dial it in and the injectors and intake would cancel each other out to some extent. I would certainly expect it to try to run at a minimum and maybe choke and have a bad time but run.

I would check the main things if you haven't: fuel, air, spark. MAF and everything else plugged in? Pull a coil pack and check spark. Fuel pressure or try starter fluid down the intake and see if it hiccups.

 

Alrighty, so turns out there is a DTC of B2799 which is visible when using techstream but not using a generic OBD2 tool like an MX. It appears this error is the result of the new ECM and Immobilizer ECU not liking their shared codes. The TIS manuals are not great at explaining steps here, its mostly focused on replacing keys/etc. All the help online says to bridge the OBD2 pin 4 and 13, which are 4 (ground) and 13 something unique to Toyota to reset this communication issue. However for 2021s I confirmed tonight there are only 7 wires in the OBD2 (pin 4 is there which is chassis ground) but no pin 13, and the other pins seems unlikely to do this reset (but possible avenue here). Before I figured out the DTC error was present, I did test the air/fuel situation and wow haha you can fill up a bowl with fuel in a second. The interesting thing is the throttle body I recorded and it would not move, so I switched out throttle bodies and initially truck turns on then TB closes. Both throttle bodies would buzz after turning off too. However I now think this is part of the immobilization to stop air flow. Now focusing on how to get the ECM and Imb. ECU to cooperate in techstream. Putting in new tunes/etc. obviously has no impact now. If this doesn't work, might be a spendy tow to the dealer lol (shameful display). Frustrating all the "fixes" on the web are really just the pin 4/13, not sure what year this stopped, but definitely hold onto your old machines for ease of maintenance!

 

Well hopefully it's not some proprietary code to work this out. What a Charlie Foxtrot!

 

Have you flashed the stock file with HPT or is it whatever was in the ecu when you got it?

 

Have not yet, once I figured out the immobilizer was active then realized flashing a different tune won't do anything.

 

wondering if flashing a new file would make it sort of reset and do a new handshake with the immobilzer. 100% just a theory.

Have you tried any of the key programming procedures just to see if it does anything?

 

I think you're spot on with the key programming, I was reading late last night about the ECM and ECU immobilizer each having a key code that they compare, so I think the key code/programming of keys needs to happen which I'll try out today. I didn't realize the two modules were comparing more than the VIN codes.

 

Haha so it turns out that you can short the new trucks (pin 4 and 13) but it has to be done with techstream. There’s an option in techstream to manual connect “TC and TE1” which is roughly the equivalent of bridging pin 4/5 and 13. Even is the same 30 min process, trying this out now. The issue I may have now is it says if you turn the ignition to on more than 20 times before doing this you may kill the immobilizer ecu, wonderful!

This method appears to be how a Toyota tech would reset the ECUs even on older cars (using techstream instead of a paperclip haha).

 

Heck yeah, yeah that worked and we're up and running using a junkyard ECU (using it's OEM tune).

(Will detail out these instructions later)

When to do this:
1) ECU is bricked (unable to link techstream, OBD2 scanners, etc. to the ECU). If unable to unbrick using other means.
2) You have a model year 2020 or 2021 (with or without a smart key appears to be the same process).
3) Pre-2020 model years (2018-2019) TIS does seem to indicate the same process, however instead of using techstream they say to bridge pin 4 and 13 manually in the OBD2 connection (what Toyota calls DLC3)

What to get:
1) Identical part number ECU. There are many part numbers of ECUs within each MY and each one is for specific configurations.
2) Techstream software (need new enough version for your year, 17.3x.xx works through 2021/2022 MY, 12.2x.xx only is good for 2017/2018 MY).
3) Dongle that Techstream accepts (tactrix openport 2.0 for example, which is what Magnuson/Orange Virus call the "legacy" dongle that comes with TVS1900 kits for new Tundras).

Procedure:
1) Disconnect battery.
2) Remove old ECU.
3) Insert new ECU. Reconnect battery. Put on high amp battery tender, ideally one that is variable based on need, ideally you can see the amp usage from the cab.
4) Use techstream to input original VIN into ECU.
5) Use techstream to short the ECUs/auto reprogram (ECU > Active Tests > "TC to TE1" On)
6) Wait 30 mins, in my case no lights flashed on the dashboard, unlike older vehicles using the paperclip shorting method (pin 4 to 13).
7) Use techstream to make sure "TC to TE1" is off
8) Turn on vehicle and allow to idle
9) Clear B2799 error code if present (should be if trying to start with new ECU).
10) Have a drink.

 

Most excellent! Might you consider consolidating what you've learned and shared into it's own post which could also be linked to in the OP? Also, as often as I flash my truck and having had bricked my ECU twice before, I have this nagging feeling that my days could be somewhat numbered and would like for this to be more accessible to myself as well as others.

 

I guess I will see tonight, hopefully its just plug and play like my last one.

 

Edit: I looked at 2018 in TIS and it looks like the same procedure "E" for registering the immobilizer ECU, just to do it manually instead of techstream, that would be interesting if its just drop in new ECM and no relearn needed. TIS was confusing for MY2021 as it just says to do procedure "F" for a new ECM, which is really just "insert key, turn on vehicle, drive for a while", however in my case you could not turn on the vehicle, maybe 2018-2019 only procedure "F" is needed.

 

@ColoradoTJ can you sticky this thread please, seems more deserving than "what intake should I pick".

 

So I installed my eBay ECM, the truck started right away, but then cut off. It just cranks now, I will upload a tune this weekend, hopefully that will do it.

 

Sounds just like what I had. I think for 2018 you can just to the paperclip method and it would reset and work (after 30 mins).

 

I finally got the chance to talk with D3Performance today and figure out why the tune @snivilous made wouldn’t work and they wanted more credits. Well turns out they had a supercharger tune I was supposed to use with way more tables and adjustability vs the stock calibration. Didn’t know that going into it but here we are. I also asked them about guys bricking their ecu’s and they said to buy their software and you’ll never have that issue again as their recovery software is pretty good, worked for me at least. Their dongle also works with techstream as well up to version 18.00.008. I was going to buy a spare ecu but after seeing what @Ponderosa_Pine went through I think I’ll just stick with that method and hope it’s works for when it bricks again.

 

There is a company online that will repair the ecm for $275.00, I'm going to send them my old unit.

 

Who is it?